BIowout preventers have a body and a pair of bonnets which are secured to the body. Rams are movably positioned in the body to move into an inner position blocking the central bore through the body and to an outer position within the body. Pistons positioned in the bonnets are connected by rods to the rams to function as the means for moving the rams. Seals are provided between the bonnets and body so that the pressure within the bonnets is contained therein.
U.S. Pat. No. 4,437,643 discloses a blowout preventer with a seal carrier positioned in a recess defined by the body and bonnet so that one of the sealing rings in the carrier seals against the body recess and the other sealing ring seals against the bonnet recess.
U.S. Pat. No. 3,997,198 discloses a swivel joint having a seal carrier for sealing between hubs 38 and 40 and is a generally tubular body with outer grooves therein to carry sealing ring for sealing against the recesses in the hubs in which the seal carrier 80 is positioned.
In such prior seal carriers it is difficult to provide proper sealing when there is a misalignment between the sealing surfaces. Where there is a misalignment and sealing is effected then there will be an increase in the extrusion gap on one side which may allow damage to the seal as a result of its extrusion between the carrier and the sealing surface.